FREQUENTLY ASKED QUESTIONS

Why should people get vaccinated against the flu?
Influenza is a highly infectious disease, each year causing significant morbidity and mortality. During an epidemic, the disease can affect 10-20% of the general population and even 40 - 50% in institutionalized elderly people. Influenza may be responsible for three to five million cases of severe illness and 250,000 to 500,000 deaths worldwide every year. Influenza vaccines are the cornerstone for the prevention of influenza, and the World Health Organization (WHO) recommends annual vaccination of high-risk persons as the best and most cost-effective strategy for reducing influenza related morbidity and mortality.

Who should be vaccinated?
Vaccination is recommended for persons at high risk. This group includes persons aged over 65, immune-compromised individuals (e.g. by HIV infection and steroid treatment), diabetics, adults and children with chronic debilitating diseases (e.g. cardiac, pulmonary and renal diseases). Vaccination is also recommended for individuals who may spread influenza to those at high risk, e.g. medical and nursing staff. Persons with a serious allergy to hen's eggs should not be vaccinated. Vaccination is generally not advised for women in their first trimester of pregnancy and children younger than 6 months.

Why is it recommended that individuals be vaccinated every year?
The antibodies produced in response to influenza vaccination decline over time and may be too low to offer adequate protection for the following year. Also, the influenza viruses continually undergo genetic changes, and immunity acquired because of previous influenza infections or the previous year's vaccination do not necessarily protect against mutated influenza viruses. As the influenza viruses change, the vaccine has to be updated on an annual basis to include the most current strains.

How does the WHO determine which strains are put into the influenza vaccine?
A global network of laboratories allows the four World Health Organization (WHO) Collaborating Centres on Influenza (Atlanta, London, Melbourne and Tokyo) to identify the viruses circulating around the world. The vaccines are updated annually based on this information so that they include the influenza virus strains that are most likely to cause widespread and severe illness.

Does the vaccine cause side effects?
Vaccination may cause a local reaction (soreness) at the injection site and, less often, a slight temperature and aching muscles for a couple of days.

How does vaccination protect you?
After vaccination, the immune system starts producing antibodies against the viral proteins from the vaccine strains. If subsequent exposure to the real virus occurs, these antibodies bind the intruding influenza virus particles so that they are eliminated before tissue is damaged; as a consequence people do not become ill or the illness is less severe.

What is the best time to be vaccinated?
It is difficult to plan vaccination campaigns as the beginning of the annual epidemic varies each year. When the vaccination campaign is planned too late, the start of the epidemic may coincide with the campaign and many vaccinees may not have had time to mount an immune response. In the Northern Hemisphere, the best time to be vaccinated is from mid-September to early November.

When should I get a flu vaccination?
Beginning each September, the flu shot should be offered to people at high risk when they are seen by health-care providers for routine care or as a result of hospitalization. The best time to get vaccinated is from October through November. Flu activity in the Europe generally peaks between late December and early March. You can still benefit from getting vaccinated after November, even if flu is present in your community. Vaccine should continue to be offered to unvaccinated people throughout the flu season as long as vaccine is still available. Once you get vaccinated, your body makes protective antibodies in about two weeks.

How effective is the flu shot?
With the flu shot, when the 'match' between vaccine and circulating strains is close, the vaccine prevents influenza in about 70%-90% of healthy persons younger than age 65 years. Among elderly persons living outside chronic-care facilities (such as nursing homes) and those persons with long-term (chronic) medical conditions, the flu shot is 30%-70% effective in preventing hospitalization for pneumonia and influenza. Among elderly nursing home residents, the flu shot is most effective in preventing severe illness, secondary complications, and deaths related to the flu. In this population, the shot can be 50%-60% effective in preventing hospitalization or pneumonia and 80% effective in preventing death from the flu.

Is it possible to get influenza if you have been vaccinated?
It is possible, particularly among older adults, to become infected after vaccination (see response to previous question). However, for those who are infected after vaccination, the disease is likely to be less severe and is less likely to result in hospitalization or death.

Does flu vaccine work right away?
No. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against influenza virus infection. In the meantime, you are still at risk for getting the flu. That's why it's better to get vaccinated early in the autumn, before the flu season really gets under way.

Can I get the flu even though I got a flu vaccine this year?
Yes. The ability of flu vaccine to protect a person depends on two things:

1) the age and health status of the person getting the vaccine, and
2) the similarity or 'match' between the virus strains in the vaccine and those in     circulation.

If I got a vaccine last year, will that protect against the flu for this year?
Vaccination last year is unlikely to protect against influenza this year because a person's immunity after influenza vaccination declines over the year after vaccination. This is one reason why it is recommended that people get vaccinated every year.

Who should not get a flu shot?
Talk with a doctor before getting a flu shot if you:

1) Have ever had a severe allergic reaction to eggs, to a previous flu shot or     have an allergy to any of the vaccine constituents
    or
2) Have a history of Guillain-Barré syndrome (GBS). If you are sick with a fever     when you go to get your flu shot, you should talk to your doctor or nurse     about getting your shot at a later date. However, you can get a flu shot at the     same time you have a respiratory illness without fever or if you have another     mild illness.

Can severe problems occur?
Life-threatening allergic reactions are very rare. Signs of serious allergic reaction can include breathing problems, hoarseness or wheezing, hives, paleness, weakness, a fast heartbeat, or dizziness. If they do occur, it is within a few minutes to a few hours after the shot. These reactions are more likely to occur among persons with a severe allergy to eggs, because the viruses used in the influenza vaccine are grown in hens' eggs. People who have had a severe reaction to eggs or to a flu shot in the past should not get a flu shot before seeing a physician. Guillain-Barré syndrome: Normally, about one person per 100,000 people per year will develop Guillain-Barré syndrome (GBS), an illness characterized by fever, nerve damage, and muscle weakness. In 1976, vaccination with the swine flu vaccine was associated with getting GBS. Several studies have been done to evaluate if other flu vaccines since 1976 were associated with GBS. Only one of the studies showed an association. That study suggested that one person out of 1 million vaccinated persons may be at risk of GBS associated with the vaccine.

Should I repeat a dose of influenza vaccine administered by an incorrect route (such as intradermal or subcutaneous)?
If the DOSE of vaccine was age appropriate, it can be counted as valid regardless of the ROUTE by which it was given.

Should I repeat a dose of influenza vaccine that is less than the recommended dose (0.25 mL for children 6-35 months; 0.5 mL for persons 36 months)?
If less than an age-appropriate dose of influenza vaccine is administered it should NOT be counted as valid regardless of the route it was given, and should be repeated, except in the case of a child being vaccinated for the first time, as noted above.

What can I do to protect myself against the flu?
By far the single best way to prevent the flu is for individuals, especially people at high risk for serious complications from the flu, to get a vaccination each autumn. However, there are other good health habits that can help prevent the flu. These are:

			Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.
			If possible, stay home from work, school, and errands when you are sick. You will help prevent others from catching your illness
			Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick.
			Washing your hands often will help protect you from germs.
			Avoid touching your eyes, nose or mouth. Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth.
			Also, antiviral medications may be used to prevent the flu.

What kills influenza virus?
Influenza virus is destroyed by heat (167-212°F [75-100°C]). In addition, several chemical germicides, including chlorine, hydrogen peroxide, detergents (soap), iodophors (iodine-based antiseptics), and alcohols are effective against influenza viruses if used in proper concentration for sufficient length of time. For example, wipes or gels with alcohol in them can be used to clean hands. The gels should be rubbed until they are dry.

Educational article provided by Solvay Pharmaceuticals.